| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * i2c-ocores.c: I2C bus driver for OpenCores I2C controller |
| * (https://opencores.org/project/i2c/overview) |
| * |
| * Peter Korsgaard <peter@korsgaard.com> |
| * |
| * Support for the GRLIB port of the controller by |
| * Andreas Larsson <andreas@gaisler.com> |
| */ |
| |
| #include <linux/clk.h> |
| #include <linux/delay.h> |
| #include <linux/err.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/errno.h> |
| #include <linux/platform_device.h> |
| #include <linux/i2c.h> |
| #include <linux/interrupt.h> |
| #include <linux/wait.h> |
| #include <linux/platform_data/i2c-ocores.h> |
| #include <linux/slab.h> |
| #include <linux/io.h> |
| #include <linux/log2.h> |
| #include <linux/spinlock.h> |
| #include <linux/jiffies.h> |
| |
| /* |
| * 'process_lock' exists because ocores_process() and ocores_process_timeout() |
| * can't run in parallel. |
| */ |
| struct ocores_i2c { |
| void __iomem *base; |
| int iobase; |
| u32 reg_shift; |
| u32 reg_io_width; |
| wait_queue_head_t wait; |
| struct i2c_adapter adap; |
| struct i2c_msg *msg; |
| int pos; |
| int nmsgs; |
| int state; /* see STATE_ */ |
| spinlock_t process_lock; |
| struct clk *clk; |
| int ip_clock_khz; |
| int bus_clock_khz; |
| void (*setreg)(struct ocores_i2c *i2c, int reg, u8 value); |
| u8 (*getreg)(struct ocores_i2c *i2c, int reg); |
| }; |
| |
| /* registers */ |
| #define OCI2C_PRELOW 0 |
| #define OCI2C_PREHIGH 1 |
| #define OCI2C_CONTROL 2 |
| #define OCI2C_DATA 3 |
| #define OCI2C_CMD 4 /* write only */ |
| #define OCI2C_STATUS 4 /* read only, same address as OCI2C_CMD */ |
| |
| #define OCI2C_CTRL_IEN 0x40 |
| #define OCI2C_CTRL_EN 0x80 |
| |
| #define OCI2C_CMD_START 0x91 |
| #define OCI2C_CMD_STOP 0x41 |
| #define OCI2C_CMD_READ 0x21 |
| #define OCI2C_CMD_WRITE 0x11 |
| #define OCI2C_CMD_READ_ACK 0x21 |
| #define OCI2C_CMD_READ_NACK 0x29 |
| #define OCI2C_CMD_IACK 0x01 |
| |
| #define OCI2C_STAT_IF 0x01 |
| #define OCI2C_STAT_TIP 0x02 |
| #define OCI2C_STAT_ARBLOST 0x20 |
| #define OCI2C_STAT_BUSY 0x40 |
| #define OCI2C_STAT_NACK 0x80 |
| |
| #define STATE_DONE 0 |
| #define STATE_START 1 |
| #define STATE_WRITE 2 |
| #define STATE_READ 3 |
| #define STATE_ERROR 4 |
| |
| #define TYPE_OCORES 0 |
| #define TYPE_GRLIB 1 |
| |
| static void oc_setreg_8(struct ocores_i2c *i2c, int reg, u8 value) |
| { |
| iowrite8(value, i2c->base + (reg << i2c->reg_shift)); |
| } |
| |
| static void oc_setreg_16(struct ocores_i2c *i2c, int reg, u8 value) |
| { |
| iowrite16(value, i2c->base + (reg << i2c->reg_shift)); |
| } |
| |
| static void oc_setreg_32(struct ocores_i2c *i2c, int reg, u8 value) |
| { |
| iowrite32(value, i2c->base + (reg << i2c->reg_shift)); |
| } |
| |
| static void oc_setreg_16be(struct ocores_i2c *i2c, int reg, u8 value) |
| { |
| iowrite16be(value, i2c->base + (reg << i2c->reg_shift)); |
| } |
| |
| static void oc_setreg_32be(struct ocores_i2c *i2c, int reg, u8 value) |
| { |
| iowrite32be(value, i2c->base + (reg << i2c->reg_shift)); |
| } |
| |
| static inline u8 oc_getreg_8(struct ocores_i2c *i2c, int reg) |
| { |
| return ioread8(i2c->base + (reg << i2c->reg_shift)); |
| } |
| |
| static inline u8 oc_getreg_16(struct ocores_i2c *i2c, int reg) |
| { |
| return ioread16(i2c->base + (reg << i2c->reg_shift)); |
| } |
| |
| static inline u8 oc_getreg_32(struct ocores_i2c *i2c, int reg) |
| { |
| return ioread32(i2c->base + (reg << i2c->reg_shift)); |
| } |
| |
| static inline u8 oc_getreg_16be(struct ocores_i2c *i2c, int reg) |
| { |
| return ioread16be(i2c->base + (reg << i2c->reg_shift)); |
| } |
| |
| static inline u8 oc_getreg_32be(struct ocores_i2c *i2c, int reg) |
| { |
| return ioread32be(i2c->base + (reg << i2c->reg_shift)); |
| } |
| |
| static void oc_setreg_io_8(struct ocores_i2c *i2c, int reg, u8 value) |
| { |
| outb(value, i2c->iobase + reg); |
| } |
| |
| static inline u8 oc_getreg_io_8(struct ocores_i2c *i2c, int reg) |
| { |
| return inb(i2c->iobase + reg); |
| } |
| |
| static inline void oc_setreg(struct ocores_i2c *i2c, int reg, u8 value) |
| { |
| i2c->setreg(i2c, reg, value); |
| } |
| |
| static inline u8 oc_getreg(struct ocores_i2c *i2c, int reg) |
| { |
| return i2c->getreg(i2c, reg); |
| } |
| |
| static void ocores_process(struct ocores_i2c *i2c, u8 stat) |
| { |
| struct i2c_msg *msg = i2c->msg; |
| unsigned long flags; |
| |
| /* |
| * If we spin here is because we are in timeout, so we are going |
| * to be in STATE_ERROR. See ocores_process_timeout() |
| */ |
| spin_lock_irqsave(&i2c->process_lock, flags); |
| |
| if ((i2c->state == STATE_DONE) || (i2c->state == STATE_ERROR)) { |
| /* stop has been sent */ |
| oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_IACK); |
| wake_up(&i2c->wait); |
| goto out; |
| } |
| |
| /* error? */ |
| if (stat & OCI2C_STAT_ARBLOST) { |
| i2c->state = STATE_ERROR; |
| oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_STOP); |
| goto out; |
| } |
| |
| if ((i2c->state == STATE_START) || (i2c->state == STATE_WRITE)) { |
| i2c->state = |
| (msg->flags & I2C_M_RD) ? STATE_READ : STATE_WRITE; |
| |
| if (stat & OCI2C_STAT_NACK) { |
| i2c->state = STATE_ERROR; |
| oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_STOP); |
| goto out; |
| } |
| } else { |
| msg->buf[i2c->pos++] = oc_getreg(i2c, OCI2C_DATA); |
| } |
| |
| /* end of msg? */ |
| if (i2c->pos == msg->len) { |
| i2c->nmsgs--; |
| i2c->msg++; |
| i2c->pos = 0; |
| msg = i2c->msg; |
| |
| if (i2c->nmsgs) { /* end? */ |
| /* send start? */ |
| if (!(msg->flags & I2C_M_NOSTART)) { |
| u8 addr = i2c_8bit_addr_from_msg(msg); |
| |
| i2c->state = STATE_START; |
| |
| oc_setreg(i2c, OCI2C_DATA, addr); |
| oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_START); |
| goto out; |
| } |
| i2c->state = (msg->flags & I2C_M_RD) |
| ? STATE_READ : STATE_WRITE; |
| } else { |
| i2c->state = STATE_DONE; |
| oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_STOP); |
| goto out; |
| } |
| } |
| |
| if (i2c->state == STATE_READ) { |
| oc_setreg(i2c, OCI2C_CMD, i2c->pos == (msg->len-1) ? |
| OCI2C_CMD_READ_NACK : OCI2C_CMD_READ_ACK); |
| } else { |
| oc_setreg(i2c, OCI2C_DATA, msg->buf[i2c->pos++]); |
| oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_WRITE); |
| } |
| |
| out: |
| spin_unlock_irqrestore(&i2c->process_lock, flags); |
| } |
| |
| static irqreturn_t ocores_isr(int irq, void *dev_id) |
| { |
| struct ocores_i2c *i2c = dev_id; |
| u8 stat = oc_getreg(i2c, OCI2C_STATUS); |
| |
| if (!(stat & OCI2C_STAT_IF)) |
| return IRQ_NONE; |
| |
| ocores_process(i2c, stat); |
| |
| return IRQ_HANDLED; |
| } |
| |
| /** |
| * Process timeout event |
| * @i2c: ocores I2C device instance |
| */ |
| static void ocores_process_timeout(struct ocores_i2c *i2c) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&i2c->process_lock, flags); |
| i2c->state = STATE_ERROR; |
| oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_STOP); |
| spin_unlock_irqrestore(&i2c->process_lock, flags); |
| } |
| |
| /** |
| * Wait until something change in a given register |
| * @i2c: ocores I2C device instance |
| * @reg: register to query |
| * @mask: bitmask to apply on register value |
| * @val: expected result |
| * @timeout: timeout in jiffies |
| * |
| * Timeout is necessary to avoid to stay here forever when the chip |
| * does not answer correctly. |
| * |
| * Return: 0 on success, -ETIMEDOUT on timeout |
| */ |
| static int ocores_wait(struct ocores_i2c *i2c, |
| int reg, u8 mask, u8 val, |
| const unsigned long timeout) |
| { |
| unsigned long j; |
| |
| j = jiffies + timeout; |
| while (1) { |
| u8 status = oc_getreg(i2c, reg); |
| |
| if ((status & mask) == val) |
| break; |
| |
| if (time_after(jiffies, j)) |
| return -ETIMEDOUT; |
| } |
| return 0; |
| } |
| |
| /** |
| * Wait until is possible to process some data |
| * @i2c: ocores I2C device instance |
| * |
| * Used when the device is in polling mode (interrupts disabled). |
| * |
| * Return: 0 on success, -ETIMEDOUT on timeout |
| */ |
| static int ocores_poll_wait(struct ocores_i2c *i2c) |
| { |
| u8 mask; |
| int err; |
| |
| if (i2c->state == STATE_DONE || i2c->state == STATE_ERROR) { |
| /* transfer is over */ |
| mask = OCI2C_STAT_BUSY; |
| } else { |
| /* on going transfer */ |
| mask = OCI2C_STAT_TIP; |
| /* |
| * We wait for the data to be transferred (8bit), |
| * then we start polling on the ACK/NACK bit |
| */ |
| udelay((8 * 1000) / i2c->bus_clock_khz); |
| } |
| |
| /* |
| * once we are here we expect to get the expected result immediately |
| * so if after 1ms we timeout then something is broken. |
| */ |
| err = ocores_wait(i2c, OCI2C_STATUS, mask, 0, msecs_to_jiffies(1)); |
| if (err) |
| dev_warn(i2c->adap.dev.parent, |
| "%s: STATUS timeout, bit 0x%x did not clear in 1ms\n", |
| __func__, mask); |
| return err; |
| } |
| |
| /** |
| * It handles an IRQ-less transfer |
| * @i2c: ocores I2C device instance |
| * |
| * Even if IRQ are disabled, the I2C OpenCore IP behavior is exactly the same |
| * (only that IRQ are not produced). This means that we can re-use entirely |
| * ocores_isr(), we just add our polling code around it. |
| * |
| * It can run in atomic context |
| */ |
| static void ocores_process_polling(struct ocores_i2c *i2c) |
| { |
| while (1) { |
| irqreturn_t ret; |
| int err; |
| |
| err = ocores_poll_wait(i2c); |
| if (err) { |
| i2c->state = STATE_ERROR; |
| break; /* timeout */ |
| } |
| |
| ret = ocores_isr(-1, i2c); |
| if (ret == IRQ_NONE) |
| break; /* all messages have been transferred */ |
| } |
| } |
| |
| static int ocores_xfer_core(struct ocores_i2c *i2c, |
| struct i2c_msg *msgs, int num, |
| bool polling) |
| { |
| int ret; |
| u8 ctrl; |
| |
| ctrl = oc_getreg(i2c, OCI2C_CONTROL); |
| if (polling) |
| oc_setreg(i2c, OCI2C_CONTROL, ctrl & ~OCI2C_CTRL_IEN); |
| else |
| oc_setreg(i2c, OCI2C_CONTROL, ctrl | OCI2C_CTRL_IEN); |
| |
| i2c->msg = msgs; |
| i2c->pos = 0; |
| i2c->nmsgs = num; |
| i2c->state = STATE_START; |
| |
| oc_setreg(i2c, OCI2C_DATA, i2c_8bit_addr_from_msg(i2c->msg)); |
| oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_START); |
| |
| if (polling) { |
| ocores_process_polling(i2c); |
| } else { |
| ret = wait_event_timeout(i2c->wait, |
| (i2c->state == STATE_ERROR) || |
| (i2c->state == STATE_DONE), HZ); |
| if (ret == 0) { |
| ocores_process_timeout(i2c); |
| return -ETIMEDOUT; |
| } |
| } |
| |
| return (i2c->state == STATE_DONE) ? num : -EIO; |
| } |
| |
| static int ocores_xfer_polling(struct i2c_adapter *adap, |
| struct i2c_msg *msgs, int num) |
| { |
| return ocores_xfer_core(i2c_get_adapdata(adap), msgs, num, true); |
| } |
| |
| static int ocores_xfer(struct i2c_adapter *adap, |
| struct i2c_msg *msgs, int num) |
| { |
| return ocores_xfer_core(i2c_get_adapdata(adap), msgs, num, false); |
| } |
| |
| static int ocores_init(struct device *dev, struct ocores_i2c *i2c) |
| { |
| int prescale; |
| int diff; |
| u8 ctrl = oc_getreg(i2c, OCI2C_CONTROL); |
| |
| /* make sure the device is disabled */ |
| ctrl &= ~(OCI2C_CTRL_EN | OCI2C_CTRL_IEN); |
| oc_setreg(i2c, OCI2C_CONTROL, ctrl); |
| |
| prescale = (i2c->ip_clock_khz / (5 * i2c->bus_clock_khz)) - 1; |
| prescale = clamp(prescale, 0, 0xffff); |
| |
| diff = i2c->ip_clock_khz / (5 * (prescale + 1)) - i2c->bus_clock_khz; |
| if (abs(diff) > i2c->bus_clock_khz / 10) { |
| dev_err(dev, |
| "Unsupported clock settings: core: %d KHz, bus: %d KHz\n", |
| i2c->ip_clock_khz, i2c->bus_clock_khz); |
| return -EINVAL; |
| } |
| |
| oc_setreg(i2c, OCI2C_PRELOW, prescale & 0xff); |
| oc_setreg(i2c, OCI2C_PREHIGH, prescale >> 8); |
| |
| /* Init the device */ |
| oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_IACK); |
| oc_setreg(i2c, OCI2C_CONTROL, ctrl | OCI2C_CTRL_EN); |
| |
| return 0; |
| } |
| |
| |
| static u32 ocores_func(struct i2c_adapter *adap) |
| { |
| return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; |
| } |
| |
| static struct i2c_algorithm ocores_algorithm = { |
| .master_xfer = ocores_xfer, |
| .master_xfer_atomic = ocores_xfer_polling, |
| .functionality = ocores_func, |
| }; |
| |
| static const struct i2c_adapter ocores_adapter = { |
| .owner = THIS_MODULE, |
| .name = "i2c-ocores", |
| .class = I2C_CLASS_DEPRECATED, |
| .algo = &ocores_algorithm, |
| }; |
| |
| static const struct of_device_id ocores_i2c_match[] = { |
| { |
| .compatible = "opencores,i2c-ocores", |
| .data = (void *)TYPE_OCORES, |
| }, |
| { |
| .compatible = "aeroflexgaisler,i2cmst", |
| .data = (void *)TYPE_GRLIB, |
| }, |
| {}, |
| }; |
| MODULE_DEVICE_TABLE(of, ocores_i2c_match); |
| |
| #ifdef CONFIG_OF |
| /* |
| * Read and write functions for the GRLIB port of the controller. Registers are |
| * 32-bit big endian and the PRELOW and PREHIGH registers are merged into one |
| * register. The subsequent registers have their offsets decreased accordingly. |
| */ |
| static u8 oc_getreg_grlib(struct ocores_i2c *i2c, int reg) |
| { |
| u32 rd; |
| int rreg = reg; |
| |
| if (reg != OCI2C_PRELOW) |
| rreg--; |
| rd = ioread32be(i2c->base + (rreg << i2c->reg_shift)); |
| if (reg == OCI2C_PREHIGH) |
| return (u8)(rd >> 8); |
| else |
| return (u8)rd; |
| } |
| |
| static void oc_setreg_grlib(struct ocores_i2c *i2c, int reg, u8 value) |
| { |
| u32 curr, wr; |
| int rreg = reg; |
| |
| if (reg != OCI2C_PRELOW) |
| rreg--; |
| if (reg == OCI2C_PRELOW || reg == OCI2C_PREHIGH) { |
| curr = ioread32be(i2c->base + (rreg << i2c->reg_shift)); |
| if (reg == OCI2C_PRELOW) |
| wr = (curr & 0xff00) | value; |
| else |
| wr = (((u32)value) << 8) | (curr & 0xff); |
| } else { |
| wr = value; |
| } |
| iowrite32be(wr, i2c->base + (rreg << i2c->reg_shift)); |
| } |
| |
| static int ocores_i2c_of_probe(struct platform_device *pdev, |
| struct ocores_i2c *i2c) |
| { |
| struct device_node *np = pdev->dev.of_node; |
| const struct of_device_id *match; |
| u32 val; |
| u32 clock_frequency; |
| bool clock_frequency_present; |
| |
| if (of_property_read_u32(np, "reg-shift", &i2c->reg_shift)) { |
| /* no 'reg-shift', check for deprecated 'regstep' */ |
| if (!of_property_read_u32(np, "regstep", &val)) { |
| if (!is_power_of_2(val)) { |
| dev_err(&pdev->dev, "invalid regstep %d\n", |
| val); |
| return -EINVAL; |
| } |
| i2c->reg_shift = ilog2(val); |
| dev_warn(&pdev->dev, |
| "regstep property deprecated, use reg-shift\n"); |
| } |
| } |
| |
| clock_frequency_present = !of_property_read_u32(np, "clock-frequency", |
| &clock_frequency); |
| i2c->bus_clock_khz = 100; |
| |
| i2c->clk = devm_clk_get(&pdev->dev, NULL); |
| |
| if (!IS_ERR(i2c->clk)) { |
| int ret = clk_prepare_enable(i2c->clk); |
| |
| if (ret) { |
| dev_err(&pdev->dev, |
| "clk_prepare_enable failed: %d\n", ret); |
| return ret; |
| } |
| i2c->ip_clock_khz = clk_get_rate(i2c->clk) / 1000; |
| if (clock_frequency_present) |
| i2c->bus_clock_khz = clock_frequency / 1000; |
| } |
| |
| if (i2c->ip_clock_khz == 0) { |
| if (of_property_read_u32(np, "opencores,ip-clock-frequency", |
| &val)) { |
| if (!clock_frequency_present) { |
| dev_err(&pdev->dev, |
| "Missing required parameter 'opencores,ip-clock-frequency'\n"); |
| clk_disable_unprepare(i2c->clk); |
| return -ENODEV; |
| } |
| i2c->ip_clock_khz = clock_frequency / 1000; |
| dev_warn(&pdev->dev, |
| "Deprecated usage of the 'clock-frequency' property, please update to 'opencores,ip-clock-frequency'\n"); |
| } else { |
| i2c->ip_clock_khz = val / 1000; |
| if (clock_frequency_present) |
| i2c->bus_clock_khz = clock_frequency / 1000; |
| } |
| } |
| |
| of_property_read_u32(pdev->dev.of_node, "reg-io-width", |
| &i2c->reg_io_width); |
| |
| match = of_match_node(ocores_i2c_match, pdev->dev.of_node); |
| if (match && (long)match->data == TYPE_GRLIB) { |
| dev_dbg(&pdev->dev, "GRLIB variant of i2c-ocores\n"); |
| i2c->setreg = oc_setreg_grlib; |
| i2c->getreg = oc_getreg_grlib; |
| } |
| |
| return 0; |
| } |
| #else |
| #define ocores_i2c_of_probe(pdev, i2c) -ENODEV |
| #endif |
| |
| static int ocores_i2c_probe(struct platform_device *pdev) |
| { |
| struct ocores_i2c *i2c; |
| struct ocores_i2c_platform_data *pdata; |
| struct resource *res; |
| int irq; |
| int ret; |
| int i; |
| |
| i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL); |
| if (!i2c) |
| return -ENOMEM; |
| |
| spin_lock_init(&i2c->process_lock); |
| |
| res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| if (res) { |
| i2c->base = devm_ioremap_resource(&pdev->dev, res); |
| if (IS_ERR(i2c->base)) |
| return PTR_ERR(i2c->base); |
| } else { |
| res = platform_get_resource(pdev, IORESOURCE_IO, 0); |
| if (!res) |
| return -EINVAL; |
| i2c->iobase = res->start; |
| if (!devm_request_region(&pdev->dev, res->start, |
| resource_size(res), |
| pdev->name)) { |
| dev_err(&pdev->dev, "Can't get I/O resource.\n"); |
| return -EBUSY; |
| } |
| i2c->setreg = oc_setreg_io_8; |
| i2c->getreg = oc_getreg_io_8; |
| } |
| |
| pdata = dev_get_platdata(&pdev->dev); |
| if (pdata) { |
| i2c->reg_shift = pdata->reg_shift; |
| i2c->reg_io_width = pdata->reg_io_width; |
| i2c->ip_clock_khz = pdata->clock_khz; |
| if (pdata->bus_khz) |
| i2c->bus_clock_khz = pdata->bus_khz; |
| else |
| i2c->bus_clock_khz = 100; |
| } else { |
| ret = ocores_i2c_of_probe(pdev, i2c); |
| if (ret) |
| return ret; |
| } |
| |
| if (i2c->reg_io_width == 0) |
| i2c->reg_io_width = 1; /* Set to default value */ |
| |
| if (!i2c->setreg || !i2c->getreg) { |
| bool be = pdata ? pdata->big_endian : |
| of_device_is_big_endian(pdev->dev.of_node); |
| |
| switch (i2c->reg_io_width) { |
| case 1: |
| i2c->setreg = oc_setreg_8; |
| i2c->getreg = oc_getreg_8; |
| break; |
| |
| case 2: |
| i2c->setreg = be ? oc_setreg_16be : oc_setreg_16; |
| i2c->getreg = be ? oc_getreg_16be : oc_getreg_16; |
| break; |
| |
| case 4: |
| i2c->setreg = be ? oc_setreg_32be : oc_setreg_32; |
| i2c->getreg = be ? oc_getreg_32be : oc_getreg_32; |
| break; |
| |
| default: |
| dev_err(&pdev->dev, "Unsupported I/O width (%d)\n", |
| i2c->reg_io_width); |
| ret = -EINVAL; |
| goto err_clk; |
| } |
| } |
| |
| init_waitqueue_head(&i2c->wait); |
| |
| irq = platform_get_irq(pdev, 0); |
| if (irq == -ENXIO) { |
| ocores_algorithm.master_xfer = ocores_xfer_polling; |
| } else { |
| if (irq < 0) |
| return irq; |
| } |
| |
| if (ocores_algorithm.master_xfer != ocores_xfer_polling) { |
| ret = devm_request_irq(&pdev->dev, irq, ocores_isr, 0, |
| pdev->name, i2c); |
| if (ret) { |
| dev_err(&pdev->dev, "Cannot claim IRQ\n"); |
| goto err_clk; |
| } |
| } |
| |
| ret = ocores_init(&pdev->dev, i2c); |
| if (ret) |
| goto err_clk; |
| |
| /* hook up driver to tree */ |
| platform_set_drvdata(pdev, i2c); |
| i2c->adap = ocores_adapter; |
| i2c_set_adapdata(&i2c->adap, i2c); |
| i2c->adap.dev.parent = &pdev->dev; |
| i2c->adap.dev.of_node = pdev->dev.of_node; |
| |
| /* add i2c adapter to i2c tree */ |
| ret = i2c_add_adapter(&i2c->adap); |
| if (ret) |
| goto err_clk; |
| |
| /* add in known devices to the bus */ |
| if (pdata) { |
| for (i = 0; i < pdata->num_devices; i++) |
| i2c_new_device(&i2c->adap, pdata->devices + i); |
| } |
| |
| return 0; |
| |
| err_clk: |
| clk_disable_unprepare(i2c->clk); |
| return ret; |
| } |
| |
| static int ocores_i2c_remove(struct platform_device *pdev) |
| { |
| struct ocores_i2c *i2c = platform_get_drvdata(pdev); |
| u8 ctrl = oc_getreg(i2c, OCI2C_CONTROL); |
| |
| /* disable i2c logic */ |
| ctrl &= ~(OCI2C_CTRL_EN | OCI2C_CTRL_IEN); |
| oc_setreg(i2c, OCI2C_CONTROL, ctrl); |
| |
| /* remove adapter & data */ |
| i2c_del_adapter(&i2c->adap); |
| |
| if (!IS_ERR(i2c->clk)) |
| clk_disable_unprepare(i2c->clk); |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_PM_SLEEP |
| static int ocores_i2c_suspend(struct device *dev) |
| { |
| struct ocores_i2c *i2c = dev_get_drvdata(dev); |
| u8 ctrl = oc_getreg(i2c, OCI2C_CONTROL); |
| |
| /* make sure the device is disabled */ |
| ctrl &= ~(OCI2C_CTRL_EN | OCI2C_CTRL_IEN); |
| oc_setreg(i2c, OCI2C_CONTROL, ctrl); |
| |
| if (!IS_ERR(i2c->clk)) |
| clk_disable_unprepare(i2c->clk); |
| return 0; |
| } |
| |
| static int ocores_i2c_resume(struct device *dev) |
| { |
| struct ocores_i2c *i2c = dev_get_drvdata(dev); |
| |
| if (!IS_ERR(i2c->clk)) { |
| unsigned long rate; |
| int ret = clk_prepare_enable(i2c->clk); |
| |
| if (ret) { |
| dev_err(dev, |
| "clk_prepare_enable failed: %d\n", ret); |
| return ret; |
| } |
| rate = clk_get_rate(i2c->clk) / 1000; |
| if (rate) |
| i2c->ip_clock_khz = rate; |
| } |
| return ocores_init(dev, i2c); |
| } |
| |
| static SIMPLE_DEV_PM_OPS(ocores_i2c_pm, ocores_i2c_suspend, ocores_i2c_resume); |
| #define OCORES_I2C_PM (&ocores_i2c_pm) |
| #else |
| #define OCORES_I2C_PM NULL |
| #endif |
| |
| static struct platform_driver ocores_i2c_driver = { |
| .probe = ocores_i2c_probe, |
| .remove = ocores_i2c_remove, |
| .driver = { |
| .name = "ocores-i2c", |
| .of_match_table = ocores_i2c_match, |
| .pm = OCORES_I2C_PM, |
| }, |
| }; |
| |
| module_platform_driver(ocores_i2c_driver); |
| |
| MODULE_AUTHOR("Peter Korsgaard <peter@korsgaard.com>"); |
| MODULE_DESCRIPTION("OpenCores I2C bus driver"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS("platform:ocores-i2c"); |